Scientists are working on a new, simpler test for breast cancer.
Most patients with suspected breast cancer have a biopsy
The test could enable doctors to diagnose the disease within minutes with the help of a scan.
It could also eliminate the need for a biopsy - the removal of a tissue sample using a needle - which many patients find uncomfortable.
Writing in the journal Medical Resonance in Medicine, they said early trials have shown that the test can identify cancerous cells.
Professor Michael Garwood and colleagues at the University of Minnesota, in the United States, use magnetic resonance spectroscopy (MRS) to identify breast cancer.
This works in much the same way as a MRI scan. It uses radio waves to produce an image of the inside of the body, differentiating between healthy and diseased tissue.
However, the MRS can also measure key chemicals in the body. In this case, it measures breast tissue levels of choline (tCho) - a chemical associated with the presence of cancer.
The researchers have found that levels of choline are higher in malignant tissue, enabling them to distinguish between healthy and diseased tissue.
"We found tCho concentrations to be significantly higher in malignancies than in benign lumps and normal breast tissues using this quantative method," said Professor Garwood.
While further research is needed, he said the test could provide doctors with a new way of diagnosing breast cancer and eliminate the need for biopsies.
"Using high magnetic fields and this spectroscopic technique may produce a powerful way to diagnose breast cancer and to monitor its response to treatment.
"We hope this technique will eventually be used to avoid unnecessary biopsy."
The researchers have used the test on 105 patients to date. They are planning further tests to see if it as good as a biopsy in identifying breast cancer.
Dr Michelle Barclay from Breakthrough Breast Cancer said an alternative to biopsies would be welcomed by patients.
"A biopsy is a surgical procedure where a sample of breast tissue is removed so it can be examined and although this can sometimes cause discomfort, it is nearly always necessary in order to determine if a tumour is cancerous or not.
"Any advances that enable accurate diagnosis of breast cancer with less invasive methods will be welcome news for women with breast cancer - we look forward to seeing the results of this study.